On 9/23/2013 1:48 AM, James Cameron wrote:
> G'day,
>
> A friend has asked for a way to announce the opening of a farm gate.
>
> I can handle the announcing, but the detection seems to have ample
> opportunities for error.
Living in a rural area I have seen the abuse gates can take. I wouldn't=20
use anything that has moving parts or has to be delicate in any way. =20
Anything buried in the path of the road of the gate is also a bad idea=20
because it might get dug up when a tractor drags something, anything=20
from a trailer to a plow could happen. It is outdoors so something that=20
is oblivious to weather conditions is also required.

I would  use a mercury tilt switch. If it is like most farm gates it=20
isn't perfectly level and there is somewhere you can place a wire and a=20
tilt switch. Could be extremely low power too if you make it a N.O.=20
system where closing powers the circuit.

Mark

--=20
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